A 46-year-old woman with a history of hiatal hernia and severe gastroesophageal reflux undergoes antireflux surgery. The reflux symptoms were refractory to medical therapy, so an endoscopic fundoplication procedure is performed. During surgery, the hiatal defect is repaired, and the gastric fundus is mobilized and wrapped around the lower esophagus to reinforce the lower esophageal sphincter. No esophageal or gastric injuries occurred, but a neural structure traversing the esophageal hiatus of the diaphragm was inadvertently injured. Which of the following is the most likely potential effect of this operative injury?
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Fundoplication is a surgical procedure used to treat refractory gastroesophageal reflux associated with an esophageal hiatal hernia. In the procedure, the esophageal hiatus is tightened, and the gastric fundus is wrapped around the lower esophageal sphincter, thereby preventing gastric acid from entering the esophagus.
However, the anterior and posterior vagal trunks (branches of the vagus nerve) also pass through the esophageal hiatus and are vulnerable to injury during fundoplication. These nerves supply parasympathetic innervation to the gastrointestinal tract and stimulate gastric muscle contraction and motility. Injury to the vagal trunks can lead to delayed gastric emptying (ie, gastroparesis), manifesting with abdominal pain, early satiety, and postprandial emesis.
(Choice B) The phrenic nerve innervates the diaphragm; it originates from the C3-C5 nerve roots and passes through the mediastinum between the heart and the lungs. It is unlikely to be injured during fundoplication because its terminal motor branches transit the venal caval foramen, not the esophageal hiatus.
(Choice C) Tonic contraction of the pelvic floor muscles (eg, levator ani) is necessary for preventing fecal incontinence. They receive parasympathetic innervation from the pelvic splanchnic nerves, not the vagus nerve, and their function would be unaffected by vagal injury.
(Choice D) The vagus nerve stimulates gastric parietal cell production of hydrochloric acid; injury may therefore lead to decreased gastric acid secretion (ie, hypochlorhydria), not increased secretion.
(Choice E) Intestinal peristalsis is mediated largely by the enteric nervous system. Although vagus nerve injury may cause transient intestinal dysmotility due to sudden loss of parasympathetic input, it would not cause long-term dysfunction.
Educational objective:
Branches of the vagus nerve (ie, anterior and posterior vagal trunks) pass through the esophageal hiatus. Damage to these branches, which can occur during esophageal hiatal hernia repair (eg, fundoplication), may result in delayed gastric emptying and gastric hypochlorhydria.